This invention relates to piering systems for shoring up building foundations and provides an improvement to the bracket assembly used in connection with such systems. Such bracket assemblies are used to transfer the weight, or load, being carried from a foundation or footing to a pier, pile or deep foundation. Its most common application is in "cradling" the footing or foundation wall of a structure, then transferring that load to a pile or pier that bears on bedrock or other load bearing strata.
Various piering systems have been employed in the past to support failed, shallow footings. Piers made of concrete, reinforced concrete, timber, steel pipe, steel tubing, and solid steel bar stock with helixes have been used in the past to support failed or failing footings, with varying degrees of success. An area of concern when using any of these piers on existing foundations is in adequately transferring the load of the foundation to the pier. Placing the pier concentrically below the existing foundation is a common solution to the problem, but sometimes becomes impractical and dangerous due to overhead limitations when working immediately below an existing foundation. Typically, an excessive excavation is required, or pier sections will be too short. Short pier sections are not only cumbersome and time consuming from an installation standpoint, but result in a pier that is of questionable flexural rigidity.
Thus, there exists a need for a bracket assembly to adequately transfer the foundation load to a pier located adjacent to the foundation. A major design consideration for such a bracket is in reducing the space it takes up between the pier and the foundation. The distance between the pier and the foundation must be kept to an absolute minimum, or a bending moment (eccentric load) of considerable magnitude will be induced into the top of the pier. This moment not only stresses the bracket unnecessarily, but also imparts a moment on the pier at a point where its lateral support from the soil is at a minimum.
There exist a number of prior art bracket assembly designs used in transferring the foundation load to a particular style of pier. See, for example, Holdeman et al, U.S. Pat. No. 5,120,163, Hamilton et al, U.S. Pat. No. 5,171,107, and West et al, U.S. Pat. No. 5,246,311. These brackets are quite adequate for their purpose, but they are each limited to a specific style or size of pier. None are adjustable to accommodate different sizes and styles of piers. Because of the potentially different conditions that may be present at a foundation supporting job, such as soil stability and depth attainable, a number of different styles and sizes of piers may be required. It can, however, become quite burdensome to have to carry a complete inventory of different bracket styles to the job site. It would be desirable to have one type of bracket which is adaptable for all types and sizes of piers.